View report page

52
While the incidence of the disease has been high in the recent
epidemic it is satisfactory to note that the mortality has been
lower than in previous epidemics. This is evident from the above
table which shows that there has been a decline in Battersea not
only in the percentage mortality but also in the severity of the
epidemics ; moreover, this decline has been progressive and indicates
the value of the measures which, so far as practicable, have
been taken in the Borough, namely, notification of cases, visitation
of the homes and removal to isolation hospitals of patients where the
home conditions are unfavourable, and co-operation with the School
Medical Authorities in dealing with cases reported from the Public
Elementary Schools.
Whooping-Cough.
During 1932 there were 783 cases of Whooping-Cough notified
under the Battersea (Measles and Whooping-Cough) Regulations,
1922, to the Medical Officer of Health and 326 additional cases were
reported from the public elementary schools and other sources.
The total number of cases notified or otherwise reported during
1932 was 1,109, as compared with 747 in 1931, 537 in 1930, 1,317
in 1929, and 1,228 in 1928, the increase in 1932 compared with 1931
being 48.5 per cent.
There were 11 deaths registered from this disease, the deathrate
being 0.07 as compared with 5 deaths and a death-rate of
0.03 in 1931, 7 deaths and a death-rate of 0.04 in 1930, 43 deaths
and a death-rate of 0.27 in 1929, and 14 deaths and a death-rate
of 0.08 in 1928.
An interesting and instructive investigation into the epidemiology
of whooping-cough was carried out by Dr. Percy Stocks,
Reader of Medical Statistics in the University of London, to whom
I am indebted for a copy of his paper; the statistical records
of four metropolitan boroughs, including Battersea, being utilised
for this purpose. Some interesting features taken from Dr. Stocks'
investigations of this dangerous disease of child life, indicate that
the notification records of the four boroughs during the last 10
years show an excess of female over male incidence amounting,
after correction for changes in the ratio of sex to age in the population
at risk, to 5 per cent. at ages up to 4 years increasing to 20 per
cent. in the eighth year, and 50 per cent. in the tenth year. The
excess was considerably greater in Greenwich than Battersea. The
age distribution of whooping cough incidence is slightly different
in the rising phases of epidemics, a somewhat larger proportion
of children aged 3 to 6 being attacked.
Children aged 4 to 6 are more liable to infect other children
in the same house than are children of other ages. A study of the
distribution of intervals between the onset of cases in the same
house leads to the conclusion that the most frequent interval is
one week. The incubation period may, it would appear, be as
short as three days, but most likely about a week. Infection after
six weeks is probably due to an exacerbation of infection due to a
superimposed catarrhal infection. About one case in every 100
is followed by another case in the same house after an interval
of between six weeks and six months.